This invention relates to an automobile anti-theft security system and, more particularly, to engine operation control systems employing encoded inputs aimed at preventing loss of the automobile due to carjacking.
Numerous devices in the prior art provide anti-theft encoded systems using encoded signals. Some of these utilize a keypad to enter a code to enable the automobile ignition system. Others permit the engine to be started but include a device which, if not actuated at the beginning of the engine start procedure, will cut-off the engine in some manner. For example, U.S. Pat. No. 4,485,887 discloses a hidden switch which must be closed after the ignition key circuit is closed. If the hidden switch is not closed, then a time delay will cause the vehicle to stop running.
Other systems are known in which a turnover mode is provided. In the turnover type of systems, as shown in U.S. Pat. No. 3,766,400 for example, primary and secondary codes are utilized. The primary code is normally utilized, but by depressing two buttons the secondary code may be used instead when the vehicle is temporarily turned over to someone else. The secondary code permits unlimited starts of the engine for use by, for example, parking lot attendants or others. The primary code is used only by the owner and, therefore, is not compromised in revealing the secondary code to others.
In a further prior art system, as shown in U.S. Pat. No. 4,446,380, a door lock code and an ignition security code are used. If the doors are unlocked, only the ignition security code is needed to start the engine. Otherwise, both codes need to be entered.
In recent times, an increasing number of carjackings have been occurring. These involve forcibly stealing an occupied car. More specifically, while the car is occupied and operated by the driver, a person sometimes referred to as a carjacker forcibly takes over the vehicle from the owner who may be entering the vehicle or sitting in it while stopped at a traffic signal, for example. Those systems which require a code to be entered to start the engine or which provide an override switch to be operated at the beginning of vehicle operation are of no concern to the carjacker because, once actuated, they permit continued and uninterrupted operation by the driver. Under such conditions the carjacker can drive a long distance to a safe place unimpeded by the security system to where the car can be "chopped up" into parts for separate resale or where the security system can be removed in its entirety or permanently bypassed so that the car can be used intact. Many of the prior art systems suffer from this drawback of providing security only when starting the engine, but are incapable of protecting the vehicle from being stolen while it is being used by the rightful owner or an authorized driver. Also, if the carjacker notices a security system in the car, or if he approaches the owner while the car has not yet been started and is unable to start the engine while the owner is in the vicinity, he can coerce the owner to reveal the code. This represents a danger to that person's safety.
To summarize the above, presently available automobile anti-theft security systems provide security only in the initial stage of operating the car. Either turn-on of the engine will be prevented or the engine will be disabled a short time after it is started unless a switch is tripped or a proper code entered. However, once this stage of operation is completed, the car will operate indefinitely until the ignition switch is turned off or the car runs out of gas. If a carjacker steals a car after its initial operating steps to deactivate the security system have been performed by the rightful driver, the carjacker is free to drive off for destinations unknown. Also, if the carjacker notices that the car has a security system installed, he may force the owner to reveal the code, thereby placing that person's safety in jeopardy.
Further, in certain if not most security systems, the ignition wire extends into the passenger compartment just as when there is no installed security system. This presents an easy theft situation for a thief knowledgeable about wire "jumping," regardless of the code-type of security system in place.
A need exists to provide an automobile security system which will not compromise the safety of the driver at the hands of the carjacker, but yet will permit easy recovery of the car should a carjacker steal the car.